1. Field of the Invention
The present invention relates to an apparatus for producing water which contains dissolved ozone (hereinafter referred to as "ozone water").
In recent years, it has been known to utilize strong oxidation effects of ozone for the purpose of disinfection, or for the purpose of processing, cleaning or other treatments of industrial products. Advantages from these utilizations exists in that ozone has strong power for the above tasks and in that those steps for removing or safening of chemicals can be omitted or substantially reduced, as compared with the cases using other chemicals except ozone, because extra ozone or released ozone rapidly decomposes in itself under usual conditions. In particular, inventors of the present invention have been paying attention to an advantage that ozone can be applied in highly accurate total amount and at highly accurate concentration to a place to be treated, when ozone is delivered after the ozone is put into the form of ozone water, and have been working to improve technologies in the related fields thereof.
2. Description of the Related Art
It is known that ozone water can be obtained by mixing and dissolving ozone into water.
Further, it is known to mix and dissolve general gases into liquids by merely employing aspirators or by utilizing typical bubbling-type methods.
However, when ozone is simply mixed and dissolved into water by using the above known methods for mixing and dissolving gases into liquids, it is difficult to provide ozone water at a stable concentration. One reason for causing this difficulty is in that ozone is hardly water-soluble and the concentration of ozone in water tends to go down rapidly because the ozone in water rapidly decomposes. In particular, in order to produce and maintain ozone water at a preferred high concentration, it is necessary to obtain higher speed of mixing and dissolving than the speed of the decomposition. However, the speed of the decomposition increases as the ozone concentration increases. Therefore, it is necessary to increase the speed of mixing and dissolving in order to increase the maximum obtainable concentration of ozone in water. However, it has been difficult to increase the speed of mixing and dissolving to an extent satisfactory for the purpose of production of ozone water, if any of the above many known methods for mixing and dissolving gases into liquids is merely employed. This is one of big problems to be solved by the present invention.
Further, many of the known methods mixing and dissolving gases into liquids defect in that they cause decrease of pressure in the gas system or in that they cause resistance in the gas fluid lines. The inventors of the present invention considered that these defects not only give load by changes of the pressure to their apparatuses but also include other problems. If the above known methods are reviewed in the viewpoint for production of ozone water, it can be foreseen that the changes of the pressure tend to unstabilize the preferable condition of equilibrium in the concentration of solution and tend to badly effect the ozone gas supply means(for example, ozone generators). They are significant problems.
And we have not found any known technologies to solve all the above mentioned problems at the same time.